As with single stepping, the previous stuff was needed because
the ARM11 code wasn't using the standard ARM base type and
register access ... but now those mechanisms work, so we can
switch out that special-purpose glue, in favor of the more
thoroughly tested/capable "standard" code.

Fixes a bug in the resume() implementation:  it wasn't handling
two of its arguments correctly, preventing the "flash erase_check"
algorithm from working.  (This code needs a *subsequent* update
for correct register handling, though... removing the confusion
about which "r2", for example, to use.)

This should resolve some "FIXME" comments too, for Thumb and
processor mode support.  It also gets rid of a nasty exit()
call; servers should only have *clean* shutdown paths.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>